Brake control mechanism



May 2, 1939. w. R. FREEMAN BRAKE CONTROL MECHANISM Original Filed March 6, 1937 2 Sheets-Sheet l INVENTOR gyRE 5 MA N ATTORNEY" may 2, 1939.

w. FREEMAN BRAKE CONTROL MECHANISM ori inal Filed Mgri'gh 6, 19s? v INVENTOR F EE MAN ATTORNEY minimum 2,156,782

\ UNITED PATENT OFFiCE e com rmcmmsu I war nnmm. University city, 110.. unmfilo flenctc St.

modem 0, 1m. Serial No. 12am llmewed September 8, 1938 My inven n r lates to braking m nlm an cross passage I'I therein. The valve spindle ex- ;more. particularly to improved means forpretends to the exterior of the casing vand has seventing release of the brakes from anapplied cured thereto a lever I 8 for opening and closing position under certain conditions. the valve. When this lever is in its full line posi- Qneof the objects of my invention is to provide tion. as shown in Figure 1 and against the lower a brake release preventing means which is adaptstop I! on casing Ii, cross passage I! of the ed to-be controlled by a predetermingldegree of spindle will place the two portions of conduit 9 vacuum in a fluid-operated motor. 8. g in communication with each other. When lever V A more specific object of my invention is to It isturned to its-dotted line position and against 10 control a fluid braking mechanism of a vehicle the upper stop 20 on casing IS, the valve spindle 10 by two valves, one valve being governed by the will be in a position where cross passage I'I thereaction of gravity when the vehicle is stopped and in will no longer connect the two portions of conby the action of inertia during deceleration of duit 0, thus closing the valve. The lever II is conthe vehicle and the other valve being controlled -nected by a rod II to the movable diaphragm 18 by a power-operated member 22 of a suction motor 23 which is adapted to be Still a further object of my invention is to operated by the suction from the manifold 24 of provide -an improved pendulum-controlled valve the internal combustion engine on the vehicle, for use in a fluid braking system to prevent the the connection being shown as a conduit 25. The release ofthe brakes from an applied p tion. lever ll also has connected thereto a spring 28 Other objects of my invention will beco e apwhich has its otherend adjus'tably secured to a 20 parentiitom the following description taken in suitable support 21-. The tension of the spring connection with the accompanying drawings in is such that the lever is maintained against stop which Figure 1 is a schematic view of a fluid' l9 (valve open position) when the degree of vacubraking system embodying my invention; Figum in the suction motor is below a predetermined as are 2 is a cross-sectional view of the pendulumvalue which, in the. present instance, will be any 26 controlled valve; Figure 3 is a cross-sectional degree of vacuum 'thatisestabiished in the maniview of the vacuum-controlled shutofl valve; fold whenthe engine is operating above idling Figure! is aview, partially in cross section; of a speed. When the engine is idling, the vacuum modified construction showing both the vacuumestablished in the manifold will be sumcient to 3Q controlled valve and the pendulum-controlled cause the suction motor to operate and overcome valve so combined as to form a single unit; Fig.- the tension of spring 28, thus moving lever I. are '5 is a cross-sectional view taken on the line ainst stop 2 t 01058 the Valveli-l of Figure 4;. Figure 6 is a, cross-sectional view The other conduit III is also provided with a on the linej-J of Figure 4; Figure 7 is ag valve 28 for closing this conduit to prevent fluid sectional-view on the line 1-1 of Figure 6; and from flowin l' il This V lv is adapted Figure 8 is an-elevational view showing'how the to b Governed y member which i under the suction motoris connected to operate one of the action of gravity when thevehicleis stopped and valves.- under the action ofinertia during deceleration of Referring 'to Figures 1 to 3, inclusive. I have the vehicle. The valve structure comprises a casshown a hydraulic braking system comprising a ing 2! having a-e 30 connected to the por- 4o master cylinder device Lot usual construction tion of conduit "leadin to h rak s. and a havinB a reservoir 2 a cylinder and a piston 4 II connected to the portion of conduit ll which in its retractedQpo'sition, as'shown, uncovleading from the master cylinder device. 'lhe era a compensating port 8 for placing the resercasing is provided with a closure plug I! in which 48 voir in communication with the cylinder ahead is iournaled a shaft 33 provided upon its inner of the piston. The piston is adapted lobe recipend with an eccentric pin 34. This pin has ror wy m ans 1 Pist n r d. connected to tatabiy mountedthereon a rubber roller 35 which the brake pedal I. The forward end oi the eyl is adapted to cover the inner end of Ii inder is connected by a conduit {toconduits 0 when the eccentric pinit on the shaft is at its so and II which in turn are'connected to the conlower point and to uncover the inner end of paso -duit Ii leading tothe actuating motors]! of the s'age II when shaft 33 is rotated through a'predebrake assemblies l3. 1 termined angle; rubber of the roller is rela- In accordance with my invention, I provide tively soft and its normal diameter is such that conduit 0 with a ;cock valve N which comprises it must be slightly deformed to place it in the I acasing ll andarotatablespindieil havinga casing. therewillbeasumcient surface of the rubber in contact with the casing wall to close passage 3| when the roller is in proper position. In order to prevent leakage through plug 32, the shaft is provided with an integral shoulder 36 and a rubber washer 31. The outer end of shaft 33 has secured thereto a pendulum 38 which is soconnected to the shaft that when the pendulum is in the vertical position assumed when the vehicle is on a level roadway, roller 35 on eccentric pin 34 will close passage 3|. A stop pin 3i! also extends from plug 32 for preventing the pendulum from swinging rearwardly beyond its vertical position.

In addition to conduits 3 and I0 for conveying fluid to the fluid motors of the braking units, there is also employed a by-pass conduit. in which is provided a one-way valve structure 4| permitting fluid to ,flow only from the master cylinder to the braking system.

In the operation of the braking system just described, when the vehicle is stopped and the engine is idling, the degree of vacuum in the manifold will be such as to operate the suction motor 23 and close shutoff valve l4. If the vehicle should now vbe on a level roadway or facing upwardly on an inclined roadway, the pendulum will assume a position against stop 39 wherein roller 36 will close passage 3|. If the brakes have been applied, fluid under pressure will be retained in the motors of the brake assemblies since conduits 3 and III are closed. Under these conditions, it will notbe necessary to hold the foot upon the brake pedal, thus permitting the operator to employ his foot to operate other instruments, as for example, the accelerator pedal. If the brakes had not been applied, they may be applied, notwithstanding the fact that both conduits 3 and iii are closed as fluid under pressure can be transferred to motors i2 th'rough by-pass 40 and non-return valve 4|. -When it is desired to start the vehicle, the usual clutch (not shown) is engaged simultaneously with the speeding up of the engine by depressing the usual accelerator mechanism. The increase in speed of the engine will cause the vacuum in the manifold to decrease to such a point that spring 26 will be able to move lever l6 downwardly and open valve i4, thus releasing the brake pressure. This action will be substantially simultaneous with the engagement of the clutch and there will be little, or no drag of the brakes when the vehicle starts;

If the vehicle is moving along a highway and it is desired to apply the brakes after removing the foot from the accelerator mechanism, the brakes will not be held in. applied position under these conditions, notwithstanding the fact that valve |4 1 will become closed due to the operation of the suction motor. As soon as the brakes are applied, the vehicle will begin to decelerate and this deceleration of the vehicle will result" in the pendulum swinging forwardly und r tn? action of inertia. Thisforward position assumed by the pendulum will place shaft 33 in a position where roller 36 uncovers passage 3|, thus permitting fluid under pressure to flow freelyuto' and from the fluid motors of the brake assemblies. Thus,

under these conditions, the brakes can be applied.

and released by movement of the brake pedal in the same manner as if neither valve |4 nor the pendulum controlled valve 26 were associated with the braking system. This is the condition which is desired under the circumstances since the operator always wants to apply and release the brakes at will during retarding of the vehicle on a highway.

Referring to the modification shown in Figures 4, 5, 6, 7, and 8, there is disclosed a construction wherein the two shutoff valves and the non-, return valve are combined in a unitary structure. The casing" is formed with a chamber 43 having an outlet 44 connected to the conduit 45 leading to the brake assemblies. This chamber is in communication by means of a. passage 46 with a second chamber 41 which is connected by a passage 48 with the conduit 49 leading from the master cylinder. A passage 50 connects chamber -43 directly withpassage 48. The passage 50 is controlled by a rubber roller 5| eccentrically mounted on the end of a shaft 52 journaled in the closure plug 53. The mounting for the roller is a U-shaped member 54 having slotted legs for receiving the rectangular portion of shaft 52 (Figure 6). As best shown in Figure '7, an I- shaped leaf spring 55 is interposed between the shaft and projections on the U-shaped member 54 in order to bias the roller against the wall of the chamber surrounding the end of passage 50.

As best shown in Figure 4, the passage 46 is controlled by a one-way valve 56 having a stem 51 extending into chamber 41. A spring 56 is interposed between the valve and the inner end of shaft 52 for biasing the valve on its seat. The stem 51 of the valve is formed with a groove 59 in which is received a projection 60 carried by a cup-shaped rotatable member 6| positioned in chamber 41 and having a sleeve 62 journaled in a bore in the casing. A shaft 63 is received by this sleeve and the inner end of the shaft carries a plate 64 for frictionally cooperating with the bottom of the cup-shaped rotatable member 6|. A rubber packing cup 65 prevents leakage of fluid between plate 64 and member 6| and a spring 66 is interposed between a star-shaped plate 61 and a closure plug 68 for biasing member 6| against the packing 69 for shaft 63.

The shaft 63 is adapted to be connected to the rotatable member 6| only when the fluid in chamber 41.-is under pressure and capable of forcing the plate into tight frictional engagement with the bottom of the cup-shaped member. The movement of shaft 63 is controlled by a pendulum 10 suitably secured to the exterior end of the shaft as shown.

As shown in Figure 8, shaft 52, which controls roller valve 5|,has a lever 1| connected to its exterior end and this lever in turn is connected to the movable element of a suction motor 12 by means of the rod 13. The suction motor is connected for operation by the internal combustion. engine by means of conduit 14. An adjustable support 16 of thevehicle by means of a bolt 11 which is screwed into plug. This support is also employed for mounting the fixed end of spring 15. The casing is so positioned ,on the support that when the vehicle is on a horizontal roadway and the pendulum is in a vertical position, valve 66 will be closed as shown in Figure 4.

In operation. if the vehicle is stopped eitheron a level or on an ascending roadway, the en e will normally be idling'and thus the suction motor 12 will be operative to cause roller 5| to close passage 60. The valve 56 will also be'closed by n brakes may,be held wherein the valve will be unatiected. It the brakes have already been applied, they will be. held so without continued pressure on the brake pedal. If they have not been applied, they may. be applied and held so by moving the brake pedal and then releasing it. This will cause fluid under pressure to pass through e 48. chamber 41, e II, valve II, chamber H and then to the brakes by way of conduit 45.- When it is desired to start the vehicle, the clutch need only be engaged and the accelerator operated in the usual manner. The increased speed of the engine causes the degree of vacuum in the mani- {old and the suction motor to be decreased which is sufllcient to cause. spring 15 to move lever II and cause the roller to be moved to a position where passage is open. The brakes now become released andthere will be no drag on the vehicle when it starts.

when the vehicle is moving along a highway and it is desired to apply the brakes to slow down, the accelerator. will first be released, thus resulting in roller 5| closing the passage. This will cause the vehicle to decelerate and as a result of the action oi inertia on the pendulum, it will be'moved forwardly as indicated by the arrow (Figure 4). If the brakes have not been applied at the time that the pendulum swings a0 forwardly. valve so win not be affected as there to a stop, the pendulum will assume its vertical position permitting valve 56 to close and the applied in a manner already referred to.f v If the vehicle is moving along a highway and the brakes are applied prior to the swinging of the pendulum forwardly as a result of the action of inertia, then, bf course, shaft 63 will be connected to member BI and valve 58 will be opened when inertia causes thependulum to move torwardly. when the vehicle is'brought to a stop, the valve will become closed;

Being aware oi the possibility of modifications in the particular structure herein described without departing'from the fundamental principles oi' my invention, Idonot intend that its scope be limited except as set ,torthby the appended claims. A. H

liaving fully described my invention. what I actuated brake .unit, a source of fluid ressure connected to the brake unit, said connecting means embodying two passages'each ,of which is 2,156,782 spring a asthependulumwillbeinaposition valves, and a pendulum ation of the-other valve.

connected to the brake unit, said connecting means embodying two es eachot which is capable oieconveylng fluid-tothe brake unit, a

. valve in each of said for preventing return flow of fluid therethroug'h, a vacuum motor for closing one or said valves when the vacuum therein is greater than a predetermined value,

and means governed by the action of gravitywhen the vehicle is stopped and by the action of inertia during deceleration or the .vehicle for controlling the other valve.

a. In a'vehicle braking mechanism, e fluidactuated brake unit, a source of fluid pressure connectedito the brake unit, said connecting means two es each of which is capable of conve'ying'fluid to the brake unit,

a valve in each of said es for preventing nal combustion engine, "a fluid-actuated brake unit and a source of fluid pressure connected to the brake unit, said connecting means embodying two es each of which is capable of conveying fluid to the brake unit, a valve in each passage for preventing return flow of fluid'therethrough, engine-operated power means for caus ing. one of said valves to be closed when the engine is idling. and means governed by the action of gravity for closing the other valve.

5. In a motor vehicle provided with an internal combustion engine, a fluid-actuated unit and a source of fluid pressure connected to the brake unit,'said connecting means embodying two passages each of which is capable of conveyingfluid to the brake unit, a valve in eachpassage for preventing return flow of fluid therethrough, engine-operatedm'eans for closing one of said for governing the oper- 6. In a vehicle braking systemsa fluid-actuated brake unit, a source of fluid pressure, a conduit' for conveyingfluid under pressure to the brakefi'init, a. valve in said mndufl; for "event ing return flovf of fluid therethrough, said valve comprising a valve seat associatedwith the conduit and a valve element in the form of aroller mounted to rotate about a deflnite axis and cobrake unit. a source otfluid pressure, a conduit in conveying fluid under pressure to the brake element aboutgits axis on or unit, a valvein said conduit for preventing return j flow ot fluid the'rethrough, said valve comprising a valve seat associated with'the conduit and a valve element in the form of a roller for cooperclaim as new and desire to secure by ters Patating with, the val e sea a a me for ent of the United States is: y L c nt i y o u s the roller on the shalt. a

1. In a vehicle braking mechanism fluid Sp t asing the roller asalnst the s at, and;

means for 'rotatlng the shaft to; 'thereby1 cause a said roller to roll on or oil the valveseat.

8. In avehicle bra fluid-actuated brake, unit, a source oi fluid ,pressurqkii conduit capable o! conveying fluid to thejbruke unit, a v p I valve in each of said as ior preventing re .jtor conveying fluid under Pressure tc-tbe brake tumflow of fluid tfierethrouflh. power-operated ,jmih'a valve in 'said conduit-tor preventingretum It means for controlling one or said valves,- and. flow oi fluid therethipugh. valve comprising gravity-actuated for controlling the other a valve seat ass'ociatedwiththei conduit and a;

' oi saidvalves. I valveelement in theiorm at a roller for coope v i a 2 .1n"a.vehicle braking mechanism, a fluidsung with the 'valvefseat. a shaft, means i I 1| brake unit, a source of fluid pressure ecdentricalifmouhtin'g'the mile!- on the shaft,

and a pendulum connected to the shaftfor controlling the roller.

9. In a vehicle braking system, a fluid-actuated brake,-a source or fluid pressure, a conduit for conveying fluid under pressure to the brake unit, a valve in said conduit for preventing return flow 'of fluid therethrough, said valve comprising a valve seat associated with the conduit and a valve element for cooperating with the valve seat, a'shaft, means for rotating the shaft, a member connected to move the valve on or ofi the seat, and means for operatively connecting the memher to the shaft by fluid pressure in said conduit. 10. In a vehicle braking system, a fluid-actuated brake, a source of fluid pressure, a conduit for conveying fluid under pressureto the brake unit, valve means associated with said conduit for preventing return flow oi! fluid therethrough, said valve means comprising a casing, a valve seat in said casing and a valve element for cooperating with the valve seat, a shaft joumaled in the wall of the casing, a pendulum for controlling the rotation of the shaft, a rotatable member connected to move the valve on or oi! the seat, and clutch means operable by fluid pressure in the casing for connecting the rotatable member to the shaft.

11. In a-vehicle braking mechahisi'n, a fluidactuated brake unit, a source of fluid pressure connected to the brake unit, said connecting means embodying two passages each or which is capable of conveying fluid to the brake unit, a

valve in one ,0! said passages, a member for controlling the movable element of the valve, a

pendulum, means operable by fluid pressure in the passage for connecting the pendulum to the member, a valve in the other passage, and means for opening and closing said last named valve. 12. In a vehicle braking mechanism, a fluidactuated brake unit, a source of fluid pressure connected to.,the brake unit, said connecting means embodying two passages each of which is capable oi'ponveying fluid to the brake unit, a valve in one of said passages, a member for controlling the movable element of the valve, a

pendulum, means operable by fluid pressure in the passage for connecting the pendulum to the member, a valve in the other passage, a suction motor for closing the last named valve and spring means for maintaining said valve open when the vacuum in said motor is less than a predetermined value. I

13.In a vehicle provided with braking apparatus having an operator-operated member, means other than the usual operator-operated member for holding the brakes applied after being applied by said operator-operated membe and comprising a movable element, a variable source of suction, control means for the holding means and comprising a vacuum-operated motor connected to the movable element and having its suction chamber continuously in communication with the source of suction whereby said suction will at all times tend to cause operation ,of the motor and movable element and the holding means to be efiective, and means for preventing said vacuum motor from operating the movable element and causing said holding means to be effective except when the vacuum therein is greater than a'predetermined degree.

14. In a vehicle provided with fluid-actuated braking apparatus comprising a fluid-actuated brake unit, a source of pressure and conduit means for connecting the source of pressure tothe brake unit, means comprising a valve associated with said conduit means for preventing the return flow of fluid from the brake unit to the source of pressure, a variable source of suction, control means for the valve and comprising a vacuum operated motor connected to operate the valve and having its suction chamber continuously in communication with the source of suction whereby said suction will at" all times tend ,to cause operation of the motor and movable element and the holding means to be effective, and means for preventing said vacuum motor from operating the valve and causing the valve to be effective to prevent return flow of fluid except when the vacuum therein is greater than a predetermined degree.

15. In a vehicle provided with fluid-actuated braking apparatus comprising a fluid-actuated brake. unit, a source of pressure and conduit means, for connecting the source of pressure to the brake unit, means comprising a valve associated with said conduit means for preventing the'return flow oi. fluid from the brake unit to the source of pressure, a variable source of suction, control means for the valve and comprising a vacuum-operated motor connected to operate the valve and continuously in communication with the source-of suction, means for preventing said vacuum motor from operating the valve and causing the valve to be eilective to prevent return flow of fluid except when the'vacuum therein is greater than a predetermined degree, and automatically operable means for causing said valve to be inefiective when the vehicle is stopped and .notwithstanding thevacuum motor is operated by the source of suction.

WALTER R. FREEMAN. 

